Micranthes idahoensis |
Micranthes subapetala |
|
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Idaho saxifrage |
Yellowstone saxifrage |
|
Habit | Plants solitary or tufted, with bulbils on caudices. | Plants solitary or in clumps, with bulbils on caudices. |
Leaves | basal; petiole flattened, 1–5 cm; blade ovate to elliptic, 1–4 cm, ± fleshy, base attenuate, margins shallowly serrate to dentate (teeth usually to 1 mm), sparsely ciliate, surfaces tangled, reddish brown-hairy abaxially, glabrate adaxially. |
basal; petiole usually indistinct, flattened, ca. 2 cm; blade ovate or elliptic to oblanceolate, 3–15 cm, fleshy, base cuneate, margins entire or minutely denticulate, ciliate, surfaces hairy. |
Inflorescences | 15+-flowered, open thyrses, (flowers ± crowded at tips, becoming more open in fruit), 10–40 cm, purple-tipped stipitate-glandular. |
30+-flowered, ± constricted (spikelike) to ± open thyrses, 20–75 cm, yellow- to pink- (rarely purplish-) tipped stipitate-glandular. |
Flowers | sepals reflexed, ovate to oblong; petals white, with 2 basal yellow spots (often faded when dried), elliptic to ovate, clawed to nearly not clawed, 1–3.5 mm, ± equaling sepals; filaments club-shaped, not petaloid, (equaling petals); pistils distinct almost to base; ovary superior, (to 1/3 adnate to hypanthium). |
sepals reflexed, ovate; petals absent, sometimes 1–5, pink to purplish, not spotted, elliptic, clawed, 1–2 mm, shorter than sepals; filaments linear, flattened; pistils connate to 1/2 their lengths; ovary inferior. |
Capsules | green to reddish purple, folliclelike. |
dark purple, valvate. |
2n | = 20. |
= 76. |
Micranthes idahoensis |
Micranthes subapetala |
|
Phenology | Flowering spring–early summer. | Flowering summer. |
Habitat | Open ledges and slopes | Subalpine and alpine meadows, wet banks, ledges |
Elevation | 500-2500 m (1600-8200 ft) | 1200-3000 m (3900-9800 ft) |
Distribution |
ID; MT; OR; WA
|
ID; MT; WY
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Discussion | Micranthes idahoensis appears to hybridize with M. occidentalis where their ranges overlap. Intermediates are abundant in some populations along the Idaho-Montana border and in Montana. This phenomenon may explain the range of filament shapes found in M. occidentalis, from flattened to sightly club-shaped. The issue of the status of M. idahoensis with respect to M. marshallii (D. L. Krause and K. I. Beamish 1972) is best deferred until a thorough study of the whole complex over its entire range is done. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Although the species is usually distinctive, some populations of Micranthes subapetala in northern Wyoming appear more similar to M. hieraciifolia than to typical M. subapetala and may need to be re-evaluated. The distributional disjunction between the two taxa is about 1600 kilometers. (Discussion copyrighted by Flora of North America; reprinted with permission.) |
Source | FNA vol. 8, p. 64. | FNA vol. 8, p. 66. |
Parent taxa | Saxifragaceae > Micranthes | Saxifragaceae > Micranthes |
Sibling taxa | ||
Synonyms | Saxifraga idahoensis, Saxifraga marshallii subsp. idahoensis, Saxifraga marshallii var. idahoensis, Saxifraga occidentalis var. idahoensis | Saxifraga subapetala, Saxifraga oregana var. subapetala, Saxifraga rydbergii |
Name authority | (Piper) Brouillet & Gornall: J. Bot. Res. Inst. Texas 1: 1020. 2007 , | (E. E. Nelson) Small: in N. L. Britton et al., N. Amer. Fl. 22: 139. 1905 , |
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